Method for the manufacture of tires



A l. C. CLINEFELTER AND H. RIES. METHOD FOR THE MANUFACTURE 0F TI'HES.

APPLICATlON EXLED JUNE 2,1921. 1,4J)7,i:"39.v Patented 1220.28, 1922 Lacasse.

STAT-ss PATENT 'ol-*Fics l JAMES C. CLIQITEFELTER AND HERBERT RIES', OF BARBERTON', 0,2310.

METHOD FDR TI-IE MANUFACTURE TIRES.

To all whom #may concern.'

Be v1t known that we, JAMES C. CLINE- rnn'rnn and HERBERT Bins, citizens of themethod in use at the present" time in the manufacture of tires of the expanded type, consists briefly in removing the tire from the` core on which it is built and inserting within the uncured tire casing, an expansible core, usually made of a number of layers of fabric and rubber. The expansible core or air bag as it is usually termed, and the tire are inserted within a mold having a cavity larger than the tire and theassembly placed in a heater or vulcanizer, the bag being connected with some suitable source of Huid pressure. yAfter the mold is closed within the' vulcanizer, pressure is admitted to the core which expands the tire outwardly against the mold cavity and the tire is cured while in expanded condition.

Tires manufactured in the manner described have many advantages, but the expansible cores or airbags are expensive to manufacture, and they have been unable, up to the present time,'to stand up under the treatment which'they receive and the successive heats to which they are subjectedv in the vulcanization of the tires, so as to average more than a -limited-number of cores.

By the present invention it isour purpose toeliminate.the expansible core or air bag and b y the methods described to construct a tire on the internal expansion principle which will possess all of the advantages of the present methods of manufacturing tires without the expense incident to the use of air bags.

Besidesthe expense connected with the manufacture of the airbags and the short life of bags, there are other disadvantages attendant upon their use, which are familiar to those.4 skilled in the art, but the faults are remedied by the manufacture "of tires in the manner disclosed herein.

Specification of Letters Patent.

Patented Feb. 28, 1922.

Application led June 2, 1921. Serial No. 474,324.

Fig. 3 is a section through the' mold and the expanded tire.

In order to carry out the invention, use is made of a buildingform of any preferred design, a core for the purpose being indicated by the numeral 1. In the center of the core, there is provided a chamber or cavity 2 which extends about the entire core and provides the means by which the pressure fluid is admitted to the tire, there being a plurality of apertures or ducts 3 which' `lead from the chamber 2 to the outer surface of the corc. At a convenient point in the inner circumference of the tire there is provided an inlet i which connect-s the chamber 2 with the source of Huid pressure by any suitable means, illustrated by the pipe or conduit 5.

The mold is illustratedat 6 and is of any usual type, the cavity within which the tire is cured being indicated by the numeral 7, it being noted at this point that the cavity is larger than the uncured tire 8, so that expansion of the tire is obtained` when fluid pressure is admitted during the curing operinterposed between the first ply of fabric and the core. This layer is indicated by thel numeral 9 and may be smoothly applied to the ply of fabric prior to its application to the core or to the core directly so that it ex tends to the bead line, to form an impervious stretchable sheath or vcover between the core and the tire carcass. If the layer of rubber pearance shown in Fig.

is applied to the core, it is buffed and cemented so as to be adhesive and over the so formed adhesive rubber layer, the tire is built up in the usual manner.

Then the tire is built it presents the ap- 2 and is ready to, be

placed in the mold. The vmold is' then -placed in the vulcanizer and the conduit to `the interior of the core is connected to the.

source of'fluid pressure. The pressure fluid passes through the'aperture 3 and the tire is expanded outwardly into the position shown Ainlig. 3, in which condition it is vulcanized in the usualV way. The layer of rubber 9 takes the place of the expansible vair bag formerly used and prevents the leakage of the fluid pressure into the tire :structure It will be noted that thelower -inside surface of the mold around the beads 10 acts to compress the beads againstthe sideof-the core, which action is augmented bythe pressure of the vulcanizer and thus forms afluid tight f joint so that lthe pressure fluid will not leak out around the edges of the tire. The layer of rubber 9 issemi-cured, as has been stated and 'during the vulcaniz'ation ofthe tire,

`this layer will receive its' ,final cure and will become an integral part of the tire structure.-

While the drawings show this invention as applied to the manufacture of clincher bead tires'.l it is obvious that with suitable changes which would suggest themselves to one skilled in the art, the invention could be adapted for the manufacture of other types of tires. It is not essential to build a complete tire prior to the expanding operation, as the rinciple of operation partially finished tire ina two cure building operation. y

It will be seen thatby the provision ofa semi-cured layer of rubber on the erforated core, it is possible to utilize flui ressure in expansion of the tire prior to and) during the curing operation without danger' of the pressure fluid finding its way into the tire for the purpose,

will apply to a panded by'internal l 1 ,aereas structure. The beads are firmly pressed against the core and the fluid will be prevented from leaking out around the edges of the casing. The expensive air bags or other .expansible cores are eliminated with all of their attendant disadvantages, and the manufacture `of the tires is cheapened and facilitated. The 4tire remains on the core on which it is built andthe labor and expense of stripping the tire from the core, as ,in former practice, is avoided.

The layer of rubber which acts as the confining medium for the fluid pressure may be` applied to the under surface of the first ply of fabric before the fabric is placed upon the core, either by calendering or placing it on the fabric by hand, or any other suitable method.

By theterm semi-cured as applied to the layer of rubber 9, it is our intention to in clude all stages of .vulcanizatiomit being possible to use a fully cured layer of rubber it being essential that the rubber be able'to confine the fluid pressure without allowing it to permeate the confining layer. f

Claims:

l. The process of manufacturing tires, comprising applyingto a form a sheet of rubber in partially cured condition, preparing they outer surface of the rubber sheetto render it adhesive, building the tire carcass about the sheet of rubber, expanding the carcass lby fluid pressure introduced between the tire, whereby the rubber sheet becomes an integral part of the tire structure.

2. Inthe process of curing tires while ex-- pressure, the' step of interposingbetween the tire structure and the source of fluid pressure, a layerof semi-- cured rubber, which becomes an integral' part of the finished tire structure.4

' JAMES C. CLINEFELTER.

- HERBERT RIES. 

